1. Field of the Invention
The present invention relates to a wiring structure where an electrical wire is wired and fixed on an insulating base member and a wiring method of producing such a wiring structure. More particularly, it relates to a wiring structure which will be appropriate for wiring a wire harness about a door trim for an automobile, the rear lamp, or the like.
2. Description of the Related Art
An ordinary wiring structure is disclosed in Japanese Unexamined Utility Model Publication (kokai) No. 5-46608. In this wiring structure, an insulating base member is disposed inside a door trim of an automobile. On a top surface of the base member, a plurality of slits are formed so as to extend along wiring routes designated for electrical wires. In wiring, the electrical wires are embedded into the slits of the base member, respectively. In this way, the electrical wires are arranged on the base member.
Similarly to the above wiring structure, Japanese Unexamined Utility Model Publication Nos. 7-20030 and 55-155022 disclose another wiring structure where the wires are fixed on the base member through the intermediary of fixtures different from the base member, for example clamps.
In the former conventional wiring structure, however, it is necessary to form many slits on the base member along each wiring route. Thus, when many wiring routes are required for the base member, then a problem arises in terms of the wiring workability. Especially, when it is required to lay the electrical wires on the so-called xe2x80x9cthree-dimensionalxe2x80x9d complicated base member, the wiring operation is too complicated to accomplish such a wiring operation on the manufacturing line for products.
On the other hand, in the latter structure where the wires are fixed on the base member by the fixtures, there is still remained a difficulty to fix the wires on the base member securely, thereby causing the unstable fixation of the wires. Additionally, due to a great number of fixtures to be handled, the wiring workability is deteriorated accordingly.
Under such a circumstance, it is therefore an object of the present invention to provide a wiring structure for an electrical wire and a wiring method of producing the wiring structure, by which it is possible to arrange the electrical wire on an insulating base member easily and certainly and also possible to facilitate the wiring of electrical wire against such a three-dimensional base member as mentioned above.
The object of the present invention described above can be accomplished by a wiring structure comprising:
an insulating base member made of an insulating material;
a plurality of projections formed integrally with the insulating base member so as to project at respective positions designated on the insulating base member; and
an electrical wire laid on the projections so that the electrical wire can be welded to the projections.
With the wiring structure mentioned above, when successively welding the electrical wire to the projections of the insulating base member, the electrical wire is secured on the insulating base member through the projections. In other words, owing to the provision of the projections on the base member, the electrical wire can be easily fixed on the insulating base member without forming any conventional slit on the insulating base member. In addition, since the wire is certainly fixed on the insulating base member through the projections formed integrally with the member, there is no need to prepare the conventional clamp etc. in order to fix the wire on the insulating base member.
In the present invention, preferably, the insulating base member is formed to have a three-dimensional structure of a designated profile and each of the projections is provided, on a top thereof, with a dint for receiving the electrical wire therein.
In this case, since the wire is retained in the respective dented tops of the projections, it is possible to easily and surely fix the electrical wire on the insulating base member even granting that it has a complicated xe2x80x9cthree-dimensionalxe2x80x9d structure.
In the present invention, more preferably, the projections are positioned along a wiring route to be designated on the insulating base member. In this case, it is possible to lay the electrical wire along the predetermined wiring route.
In the present invention, more preferably, the insulating member has a bore formed on the wiring route, for dividing the electrical wire into a plurality of wire portions. In this case, owing to the provision of the bore, it is possible to define a plurality of wiring routes consisting of the wire portions, on the insulating base member.
In the present invention, more preferably, the insulating member is provided, in the bore, with a plurality of notches for engagement with a lamp holder for an automobile. In this case, it is possible to support the lamp holder by the bore of the insulating base member.
According to the present invention, there is also provided a method of producing the above wiring structure, the method comprising the steps of:
integral-molding an insulating base member provided with a plurality of projections at designated positions on the insulating base member;
preparing an electrical wire;
successively welding the electrical wire onto the projections of the insulating base member while laying the electrical wire on the projections. In the above-mentioned method, since the wiring is carried out while holding the wire by the projections, the workability in wiring can be improved, thereby allowing the automatic wiring of the electrical wire. In the integral-molding step, preferably, the insulating base member is formed to have a three-dimensional structure of a designated profile by a vacuum molding method. In this case, it is possible to wire the electrical wire on the insulating base member having the complicated xe2x80x9cthree-dimensionalxe2x80x9d structure. That is, the accurately-wired product can be produced at a low cost.
In the above-mentioned method, preferably, the projections are positioned along a wiring route to be designated on the insulating base member. Also in this case, it is possible to lay the electrical wire along the predetermined wiring route.
In the above-mentioned method, more preferably, it further comprises the step of punching the insulating base member having the electrical wire welded on the projections, thereby to form a bore positioned on the wiring route, for dividing the electrical wire into a plurality of wire portions. In this case, owing to the provision of the bore, it is possible to define a plurality of wiring routes consisting of the wire portions, on the insulating base member.
In the above-mentioned method, it is preferable that the welding step is carried by using an ultrasonic welding machine. In this case, the welding operation for the wire can be simplified due to the facility of ultrasonic welding.
These and other objects and features of the present invention will become more fully apparent from the following description and appended claims taken in conjunction with the accompany drawings.